Thermal fan



Oct. 12, 1965 o. A. KENDALL 3,211,891

THERMAL FAN Filed July 5, 1963 Oakley A. Kendall INVENTOR.

Attorney:

United States Patent f 3,211,891 THERMAL FAN Oakley A. Kendall, Machine & Electric, Huntsville, Wash. Filed July 5, 1963, Ser. No. 293,094 3 Claims. '(Cl. 219-372) This invention primarily relates to a new and novel type of apparatus for propelling and heating fluid. -There are many devices on the market today which comprise various types'of heating units. The most common type includes a combination of a separate stationary heating unit and some sort of blower means whereby heated fluid may be propelled to a location for performing its function. However, the present invention seeks to greatly simplify this arrangement by combining the means for irnpelling and heating a fluid into a single unit. More particularly, it is the primary object of this invention to disclose apparatus for impelling and heating fluid which partakes of the nature of a fan in which the impelling blades themselves comprise a continuous electrical resistance strip or a plurality of strips whereby the heat generated by passage of an electric current through said strip or strips will simultaneously heat the fluid as it is being impelled.

A further object of this invention resides in an instrument of the character indicated wherein the fan disclosed may be of the squirrel-cage type thereby being readily adaptable to a wide range of air volume delivery.

Yet another object of this invention resides in the fact that such a heating device is so simple in construction and high in efliciency as to make it commercially feasible to manufacture.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of the instrument comprising the subject matter of the instant invention.

FIGURE 2 is a sectional view taken substantially along the plane indicated by the line 22 of FIGURE 1.

FIGURE 3 illustrates a schematic wiring diagram for supplying electrical energy to the electrical resistance strip which can be used in the instant invention.

Referring now to the drawings in detail, the heating device may be suitably housed in a housing such as illustrated by the numeral 10. Said housing comprises a fluid inlet opening such as 12 and a suitable fluid discharge conduit or duct disposed thereabove such as indicated at 14. If desired, the inlet opening 12 may be partially closed by a screen suchas 16 to prevent large particles from entering the housing 10.

A pair of axially spaced rings or rotor rims such as 18 are mounted for rotation within the housing by means of a power shaft such as 20 driven by a suitable electrical motor such as indicated at 22 which is mounted upon the housing 10 by any suitable bracket such as shown at 24. Each of the spaced rings 18 are supported by a plurality of radial support arms 26 extending from the circumference of the rings to a centrally located hub, such as 28 which may be keyed or otherwise suitably connected to the power shaft 20.

A continuous electrical resistance strip such as indicated generally by the numeral 30 may be threaded back and forth between said rings about the circumference thereof to form a plurality of fluid impelling surfaces or blades 32. It should be noted that the rotational axis of the rings 18 is in axial alignment with the fluid inlet opening 12. Therefore, by rotation of the rings 18, air

Patented Oct. 12, 1965 will be sucked into the housing 10 through the inlet opening 12 and impelled by the blades 32 in a direction normal to the axis of rotation of the rings. More particularly, as shown in FIGURE 2, the fluid indicated by the arrows 34 will be impelled by the exemplary fan tangential to the circumference of the rings 18 into the conduit 14. Also, although a continuous electrical resistance strip has been illustrated, it should be apparent that the same results may be obtained by using a plurality of spaced strips about the circumference of each of the rings 18 and extending therebetween provided such strips are electrically connected by suitable conductors.

With specific reference to FIGURE 3, electrical energy is adapted to be supplied to the electrical resistance strip 32 for heating thereof through a pair of conducting ring elements 36 and 38 which may be mounted for rotation with the electrical strip by mounting them upon the power shaft 20. As shown, the ring 36 may be electrically connected by a suitable conductor such as 40 to one end of the strip 30 and similarly, the ring element 38 may be connected by a conductor 42 to the opposite end of the strip 30. A second pair of conductors 44 and 46 connected to a suitable source of electrical energy are adapted to be respectively connected to stationary brushes 48 and 50. Said brushes are adapted to ride on the rings 36 and 38 providing a continuous electrical connection to the opposite ends of the electrical resistance strip 30.

It should now be apparent that a highly efficient thermal type fan is provided which will simultaneously impel the fluid passing therethrough by tangential ducted discharge of the fluid into the conduit 14 at a high velocity. In this regard it should be appreciated that the blades 32 perform dual functions compatible with each other. Thus, heat is deliberately generated in the blades for transfer through air flow induced by its movement. The blade areas, angles and speed as well as the resistivity of the material will be selected accordingly to obtain the desired balance of volumetric outflow and fluid temperature. To achieve these ends, the blades 32 are radially and circumferentially spaced and angled by the proper amount in the direction of movement producing the ducted, tangential outflow as shown by arrows 34 in FIG- URE 2. As illustrated in FIGURE 1, the housing 10 may be attached to any suitable means with which the fan is to supply heated fluid.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A device for impelling and heating fluid comprising housing means including a tangential outlet conduit and an axial inlet opening therebelow, fluid impelling blade means rotatably mounted in said housing for inducing flow of fluid at a substantial flow rate in the outlet conduit, said blade means being formed from a continuous electrical resistance material having electric circuit means attached thereto for generating heat therein to elevate the temperature of the fluid in said outlet conduit substantially above the temperature of the fluid entering entering the inlet opening, and a pair of axially spaced rings mounted on a power shaft rotatable in said housing means, said power shaft projecting from the housing means opposite said inlet opening, said electrical resistance material being threaded back and forth between said rings about the circumference thereof to form a plurality of fluid impelling surfaces angled in the direction of rotation of said rings to discharge the fluid into the outlet conduit in a direction normal thereto.

2. The device of claim 1 wherein said power shaft is driven by electric motor means mounted on said housing means.

3. A ducted, forced-flow heating device comprising, an annular casing having opposite axial end walls forming an enclosed chamber, one of said axial end walls having an inlet opening, a motor secured to the other end wall having a power shaft rotatably mounted therein and projecting into the chamber, an outlet duct tangentially connected to the casing above the inlet opening for communication with the chamber through a circumferential portion of the casing above the power shaft, a rotor fixed to said power shaft having axially spaced annular rim' portions, a continuous strip of material hav- -ing blade portions extending between said rim portions of the rotor and connecting portions secured to the rim portions and circumferentially spacing the blade portions, said material having an electrical resistivity property for heating the blade portions in response to passage of electrical current therethrough, means for supplying electrical energy to the strip of material to generate heat in 4 said blade portions thereof, said blade portions being positioned at a forward angle to a radial line from the power shaft in the direction of rotation thereof for discharge of fluid at a substantial velocity into the outlet 5 duct, whereby fluid heated by passage between said blade portions within the casing is supplied by the outlet duct at a substantial volumetric flow rate in response to rotation of the motor. 7

References Cited by the Examiner UNITED STATES PATENTS 54/01), printed March 30, 1961.

RICHARD M. WOOD, Primary Examiner. ANTHONY BA-RTIS, Examiner. 

1. A DEVICE FOR IMPELLING AND HEATING FLUID COMPRISING HOUSING MEANS INCLUDING A TANGENTIAL OUTLET CONDUIT AND AN AXIAL INLET OPENING THEREBELOW, FLUID IMPELLING BLADE MEANS ROTATABLY MOUNTED IN SAID HOUSING FOR INDUCING FLOW OF FLUID AT A SUBSTANTIAL FLOW RATE IN THE OUTLET CONDUIT, SAID BLADE MEANS BEING FORMED FROM A CONTINUOUS ELECTRICAL RESISTANCE MATERIAL HAVING ELECTRIC CIRCUIT MEANS ATTACHED THERETO FOR GENERATING HEAT THEREIN TO ELEVATE THE TEMPERATURE OF THE FLUID IN SAID OUTLET CONDUIT SUBSTANTIALLY ABOVE THE TEMPERATURE OF THE FLUID ENTERING ENTERING THE INLET OPENING, AND A PAIR OF AXIALLY SPACED RINGS MOUNTED ON A POWER SHAFT ROTATABLE IN SAID HOUSING MEANS, SAID POWER SHAFT PROJECTING FROM THE HOUSING MEANS OPPOSITE SAID INLET OPENING, SAID ELECTRICAL RESISTANCE MATERIAL BEING THREADED BACK AND FORTH BETWEEN SAID RINGS ABOUT THE CIRCUMFERENCE THEREOF TO FORM A PLURALITY OF FLUID IMPELLING SURFACES ANGLED IN THE DIRECTION OF ROTATION OF SAID RINGS TO DISCHARGE THE FLUID INTO THE OUTLET CONDUIT IN A DIRECTION NORMAL THERETO. 